How many moves does it take to swap over some red and blue frogs? Do you have a method?
Can you picture how to order the cards to reproduce Charlie's card trick for yourself?
Generate three random numbers to determine the side lengths of a triangle. What triangles can you draw?
Charlie likes tablecloths that use as many colours as possible, but insists that his tablecloths have some symmetry. Can you work out how many colours he needs for different tablecloth designs?